AGA To Go. Now thats getting a bit silly, where one can still purchase new-old stock 1200 in a smaller footprint package.
To be honest the best setup would be A500 as it is for compatibility with older games and return to the past feeling if u grew up with the A500 and a A1200 for hdd / accelerator / updated WB and AGA classic computing. (whdload if you get lazy inserting disks into A500 (: ) If you go all out upgrading the A500 you STILL need to go all out to upgrade the A1200. x2 the money spent.